Re: BUG #17185: PostgreSQL performance GNU vs LLVM

Hi All
I would like to know any comments or inputs #17185
I understand the benefits of using JIT - TPC-H from the link:
https://www.pgcon.org/2017/schedule/attachments/467_PGCon%202017-05-26%2015-00%20ISPRAS%20Dynamic%20Compilation%20of%20SQL%20Queries%20in%20PostgreSQL%20Using%20LLVM%20JIT.pdf
<https://www.pgcon.org/2017/schedule/attachments/467_PGCon%202017-05-26%2015-00%20ISPRAS%20Dynamic%20Compilation%20of%20SQL%20Queries%20in%20PostgreSQL%20Using%20LLVM%20JIT.pdf>
I would like to know TPC-C performance GCC vs Clang(llvm).(# reference the
below mail)

Best regards
Arjun

On Wednesday, September 8, 2021, PG Bug reporting form <
noreply(at)postgresql(dot)org> wrote:

> The following bug has been logged on the website:
>
> Bug reference: 17185
> Logged by: arjun shetty
> Email address: arjunshetty955(at)gmail(dot)com
> PostgreSQL version: 13.4
> Operating system: RHEL8.4
> Description:
>
> TPCH Results(Query Response Time(Q1 to Q22):
> -------------
> VU GCC Clang clang-with-llvm Clang(make file
> code removed -flto
> =thin to flto)
> vu
> 1 7185 6349 4410 9984
> 2 7302 7352 4307 9990
> 3 6233 6749 4544 9698
> 4 6701 6328 3701 10878
> 5 7105 7376 5829 10991
>
>
> Note: clang-with-llvm: JIT OFF.
>
>
> TPCC Results(NOPM)
> ------------------
> vu GCC Clang Clang-with-llvm
>
> Clang(make file code removed -flto =thin to flto(regluar flto)
> 16 921489 967234 946472
> 963300
> 52 1655840 1779333 1683924
> 1713926
> 68 1765030 1787377 1810060
> 1835825
> 170 1894382 1986746 2034823
> 1938886
> 192 1739617 1901906 1929656
> 1912524
> 210 1610512 1801849 1674440
> 1715523
> 230 1830690 1825760 1799097
> 1708821
>
> 1.Regaular LTO not performs better than Thin LTO ? is regular LTO not
> supported in postgresql?
> 2.Is specific reason need to use -flto=thin(clan13)?
> 3.TPCH(Clang-llvm)performs better than GCC/Clang(others) but why
> TPCC(Clang-llvm) not performs better than GCC/Clang-other (performance
> deviation is less)
>
> the results captured in bare Metal(HP Environment) and benchmark Env
> HammerDbv4.2
>
>